Promoting Positive Coexistence in Wireless Networks: A Submission for Joint Forum

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 Project: IEEE P802.15 Working Group for Wireless Specialty Networks (WSN) Submission Title: Thoughts for Consideration in the Joint 802.11/802.15 Coex Forum Submitted: 12 November 2024 Source: Benjamin A. Rolfe (Blind Creek Associates) Contact: Voice: [deprecated], E-Mail: ben.rolfe @ ieee.org Re: Coexistence of 802.11 and 802.15 Abstract: Contribution providing thoughts for consideration in moving forward in promoting positive coexistence outcomes Purpose: Contribute to peach and harmony within 802, effective spectrum utilization, and world peace Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. B. Rolfe, BCA Submission Slide 1

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 Thoughts for Consideration in the Joint 802.11/802.15 Coex Forum Author: Name Affiliation Address Email Blind Creek Associates Benjamin Rolfe Los Gatos, CA ben.rolfe @ ieee.org B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 FCC Subpart E Interesting facts (not the entire world, but not insignificant) B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 5.925-7.125 GHz, 5.15-5.35 GHz, and 5.47-5.895 GHz in the US FCC Part 15 Subpart C (wideband devices) FCC Part 15 Subpart E (U-NII) FCC Part 15 Subpart F (UWB) 3.1 10.6 10.6 5.15 7.125 5.925 UWB Subpart F U-NII WIdeband 7.250 GHz B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 US Title 47, Chapter 1, Subchapter A, Part 15, Subpart E Unlicensed National Information Infrastructure Devices Contention based protocol B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 US Title 47, Chapter 1, Subchapter A, Part 15, Subpart E Unlicensed National Information Infrastructure Devices Contention Based Protocol: A protocol that allows multiple users to share the same spectrum by defining the events that must occur when two or more transmitters attempt to simultaneously access the same channel and establishing rules by which a transmitter provides reasonable opportunities for other transmitters to operate. Such a protocol may consist of procedures for initiating new transmissions, procedures for determining the state of the channel (available or unavailable), and procedures for managing retransmissions in the event of a busy channel. 15.407 General technical requirements. (d) Operational restrictions for 6 GHz U-NII devices. 6) All U-NII transmitters, except for standard power access points and fixed client devices, operating in the 5.925-7.125 GHz band must employ a contention-based protocol. B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 US Title 47, Chapter 1, Subchapter A, Part 15, Subpart E Unlicensed National Information Infrastructure Devices That s it, that s all the FCC rulessay about Contention Based Protocols . What are the technical requirements? Did you find listen before talk in there? may consist of procedures for determining the state of the channel FCC has documented a method that will be acceptable for demonstrating compliance with 15.407 (d)(6) in KDB 987594 D02 U-NII 6 GHz EMC Measurement v03, GUIDELINES FOR COMPLIANCE TESTING OF UNLICENSED NATIONAL INFORMATION INFRASTRUCTURE 6 GHz (U-NII) DEVICES PART 15, SUBPART E B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 KDB 987594 D02 U-NII 6 GHz EMC Measurement v03 Covers indoor access points, subordinate devices, all client devices (except for Fixed clients), and VLP devices operating in the 5.925- 7.125 GHz band Stated purpose is to avoid co-channel interference with incumbent devices sharing the band. incumbent in FCC land means licensed (priority) users of the band. From the KDB: Unlicensed devices must detect co-channel radio frequency power that is at least -62 dBm or lower. See the next slide summarizing the test procedure for clarification. Must detect RF energy throughout their intended operating channel 90% or greater certainty (9 out of 10 tries) B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 KDB 987594 D02 U-NII 6 GHz EMC Measurement v03 40 MHz RX BW 10 MHZ AWGN -62 dBm 2 MHz RX BW B. Rolfe, BCA Submission 9

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 KDB 987594: Contention based protocol KDB 987594 D02 U-NII 6 GHz EMC Measurement v03 section I, contention based protocol Test method in a nutshell: A 10 MHz-wide additive white Gaussian noise (AWGN) signal is selected to simulate and represent incumbent transmission Where DUT signal is wider than 10 MHz, test may be repeated with AWGN signal at different center frequencies within the DUT channel (up to 3) If DUT signal is less than 10 MHz, test only at one frequency is required Run DUT at a constant duty cycle Ramp up AWGN signal until DUT ceases transmission: If it stops at or before the 10 MHz-wide AWGN signal is at -62 dBm, pass B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 KDB 987594: Contention based protocol This is one way to demonstrate implementation of a contention based protocol, not the only way Aligns with an industry alliance conformance test procedure Has been referenced in approvals of non-802.11 based systems B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 Quick look: VLP Approvals (11-Nov-2024) Jan 1 to November 11, 2024 Search on 6VL type, Part 15E, 6 GHz band This will include anything that includes VLP 117 devices approved The first dozen or so to show up (public) were not 802.11ax Determined by examining test report Of current search spot checked about half Most include 802.11ax All but 2 include NB U-NII Caveats: If requested, FCC will not make approval public for 6 months Many of the search results look like variations of the same or similar (multo-radio) products Search on 6VL without Part 15E This includes applications for VLP only 10 results, all NB UNII Not a surprise any 802.11ax w/VLP will also have LPI B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 Quick look: VLP Approvals Statement of the obvious Unlikely an of these devices comply with mandates in our standards that are yet to be written Unlikely these devices are going away All look to be commodity consumer devices Possible that *some* of these devices can accommodate *some) updates via firmware/software The higher in the protocol stack the more likely it s not cast in sand Very likely that there are variations of these products approved or in process for other markets outside North America The U-NII 5 + 7 VLP Narrow Band train has left the station! B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 Scope of effect: what can we do in 802? First principles: IEEE 802 is not a regulatory body Ultimately our standards are recommendations that can be used or ignored 802 standards are adopted when they are useful, make sense, and can be implemented Real world: if something in our standard doesn t work for a purpose, something else is used (parts of our standard are ignored or used with changes) Sometimes the workaround comes back into 802 to update our standards The best thing we can do is make good technical sense B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 Scope of effect: what can we do in 802? What we can do in 802 Understand the technology Realistically evaluate the risks and potential mitigations There are multiple mitigations possible No single mitigation always works Single dimension thinking leads to unsustainable approaches Develop useful coexistence strategies that are beneficial for all Re-review the mechanisms already present in our standards Understanding of practical mitigations is a likely outcome Direct engagement between .11 and .15 can be beneficial Need an all inclusive approach (the problem is larger than either WG) B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 What we can, but should not, do Spin our wheels blaming "the other working group", "proving" that our favorite technology is intolerant and vulnerable Likely outcomes include anxiety, bad PR for 802, with a side effect of loss of credibility and influence outside of 802 Actual coexistence improvements won't happen Fixate on only one possible solution Effective coexistence requires a depth of tool kit capabilities RF environments, application needs, and spectrum regulations vary greatly Impede the progress of any 802 project To be effective we must be positive and inclusive Always do what we ve always done expecting a different outcome B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 A better approach Joint efforts with sessions with objective technical discussions Engage in mutual discussions in joint sessions Participation from both 802.11 and 802.15 working groups Need the difference perspectives (need input) Spread the word (more input == better outcomes) Make joint recommendations that have benefit both ways Understand the widely varying environments, regulatory requirements, application needs, and other differences that make different standards different and relevant (and equal in importance) B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 What we can t do in 802 Make regulations Force anyone to use what we put in our standards Band together within a working group to block progress of a project in another working group project (IEEE SA rules) Affect the behavior of anyone for whom or mandates make no sense for their needs Ultimately products are bound by regulatory agency rules, not our standards Stuff that doesn't work for their application will be ignored Change gravity, the rate of decay of the earth's orbit around the sun, or the fundamental reality of the above points (sorry Marc ;-) That doesn t mean we can not have a positive impact and positive outcomes! B. Rolfe, BCA Submission

Doc Numbers: 15-24-0637-00 and 11-24-1940-00 Nov 2024 Reaching for positive outcomes Education is good: help each other learn: can and should be part of the joint sessions. It s a learning process! B. Rolfe, BCA Submission